This invention relates to a heat exchanger with a tube cleaning element capturing cage interconnection.
It is known from some of the above-identified patents to connect individual elongated cleaning element capturing cages or baskets to both ends of longitudinally extending tubes disposed in a heat exchanger housing. The tube ends are held in position at both ends by transverse tube sheets. The baskets are adapted to contain shuttleable cleaning elements such as brushes. Fluid flowing in one direction through the tubes keeps the cleaning elements captured within their respective basket chambers, while the fluid discharges outwardly through slot-like openings in the basket walls. Upon reversal of fluid flow, the brushes are forced out of their baskets and through the tubes to the baskets at the opposite tube ends to thereby perform a tube cleaning action.
It is also known, as in Leitner U.S. Pat. No. 4,353,414, that when a rotatable pressure reversing distributor arm rotates between compartmentalized tube ends, bundles of baskets may be provided with interconnected lips which form an elongated contact surface which is registerable with the distributor arm. The baskets are shown as being press fit into the tube ends, such as in Baron et al U.S. Pat. No. 4,382,465.
When the baskets are press fit into the heat exchanger tubes, an adhesive such as an epoxy, has normally been utilized in the connection to rigidly secure the baskets to the tube ends. Considering that many hundreds of tubes and baskets may be needed for each installation, the extra step of applying the adhesive is time consuming and costly.
In addition, heretofore the tube ends throughout an exchanger have been of the same diameter so that the techniques for basket attachment would be the same for all tubes. Now, however, some heat exchangers have been constructed with tubes having varying diameter ends, creating substantial difficulties for attachment of baskets, all of which are basically the same size.
It is a task of the present invention to provide a construction which permits a labor-saving reduction in securing the baskets to the tube ends of a heat exchanger, regardless of whether the tube ends are of varying diameters or not.
In accordance with the various aspects of the invention, when the tube ends are of varying diameters, along the plane of a tube sheet, some baskets, which are slightly flexible, are press fit into the larger diameter tube ends and an adhesive used to rigidly secure the members together, as heretofore. In addition, other baskets are loosely slipped over the smaller diameter tube ends. However, an adhesive is not necessary to rigidly fix these latter baskets in place. Instead, a connector device joins baskets which are not rigidly fixed against axial movement to those that are, so that the latter support the former in rigid interconnecting relationship.
In the embodiment disclosed in the drawings the connectors extend laterally across the outer end portions of the basket chambers which confine the shuttleable cleaning elements. The connectors comprise elongated rods or the like which extend through stop devices mounted to the outer basket ends, said stop devices also functioning to retain the cleaning elements in their respective baskets.
If the tube ends are all of the same diameter, only some of the baskets need be rigidly secured to the tube ends by an adhesive, with the other baskets interconnected thereto by connectors as described above.